Sick Day Rules for Diabetes Medications are evidence-based protocols developed by the American Diabetes Association (ADA) to prevent diabetic ketoacidosis (DKA) and acute kidney injury (AKI) during illness. These guidelines were last updated in January 2023 and are critical for avoiding life-threatening complications.
When you’re sick, your body’s stress response can turn your diabetes medications into a hidden danger. According to CDC data, 12.7% of diabetes-related hospitalizations happen because of medication mistakes during illness. Research shows people with diabetes face a 300% higher risk of DKA and 200% higher risk of AKI during acute illness. These complications escalate fast-especially if you don’t adjust your meds properly. Let’s break down exactly what to do.
Why Sick Days Are Dangerous for People with Diabetes
Illness triggers stress hormones that spike blood sugar. At the same time, vomiting, diarrhea, or fever can dehydrate you. This combo makes diabetes medications behave unpredictably. A 2022 JAMA Internal Medicine study of 47,892 hospital admissions found 30% of diabetes-related ER visits during illness were due to medication errors. For example, continuing metformin while dehydrated can cause lactic acidosis-a rare but deadly condition. Similarly, SGLT2 inhibitors increase DKA risk when you’re not drinking enough fluids. The key is knowing which meds to stop, reduce, or keep taking.
Medication-Specific Rules for Illness
Not all diabetes drugs need the same handling when you’re sick. Here’s what the ADA recommends:
| Medication Class | Risk During Illness | Action Required | Critical Thresholds |
|---|---|---|---|
| Metformin | 8.3-fold increased risk of lactic acidosis | Discontinue immediately with vomiting, diarrhea, or fever | Serum creatinine >1.5 mg/dL |
| SGLT2 Inhibitors (e.g., Jardiance, Farxiga) | 7.2-fold increased DKA risk | Stop at first sign of illness | Any fever or dehydration |
| ACE Inhibitors/ARBs (e.g., lisinopril, losartan) | 40% higher AKI risk | Pause when fluid intake <1,500 mL/day | Serum creatinine rise >0.3 mg/dL in 48 hours |
| Insulin (Type 1) | Basal rate must increase during illness | 10-20% higher basal dose every 4 hours if blood glucose >270 mg/dL | Blood glucose consistently above 15 mmol/L (270 mg/dL) |
| Insulin (Type 2) | 68% require dose adjustments | Individualized changes based on blood glucose trends | Consult provider before adjusting |
Important: Never guess. If you’re unsure, call your doctor. For example, a patient in Dallas recently went to the ER after continuing metformin during a stomach flu. Her creatinine spiked to 1.8 mg/dL, requiring dialysis. This is why clear rules matter.
Monitoring Blood Sugar and Ketones During Illness
Checking your blood sugar isn’t optional when sick. You need to test every 2-4 hours-even if you feel fine. The ADA recommends a target range of 100-180 mg/dL during illness. If your blood sugar stays above 240 mg/dL, test for ketones immediately. Use urine strips or a blood ketone meter. Urine ketones >1.5 mmol/L or blood ketones >0.6 mmol/L mean you need emergency care. A 2023 Diabetes Care trial found patients who tested ketones every 4 hours reduced DKA risk by 73% compared to those who checked less often.
Here’s a real example: Sarah, a type 1 diabetic in Texas, developed a fever during flu season. She checked her blood sugar every 2 hours and noticed ketones at 0.8 mmol/L. She called her endocrinologist right away and adjusted her insulin. This prevented hospitalization. Don’t wait-test early and often.
Emergency Signs That Require Immediate Medical Help
Know when to call 911 or go to the ER. These symptoms need urgent attention:
- Blood glucose <70 mg/dL that doesn’t improve after 30g of fast-acting carbs (like juice or glucose tablets)
- Ketones >1.5 mmol/L that persist for over 2 hours
- Vomiting for more than 4 hours straight
- Diarrhea for more than 6 hours
- Confusion, rapid breathing, or fruity-smelling breath (signs of DKA)
- Reduced urine output or swelling in legs (signs of AKI)
In 2023, CDC data showed 27% of diabetes-related hospitalizations could’ve been avoided if patients recognized these signs earlier. For instance, a 62-year-old man in Florida ignored diarrhea for 8 hours while on lisinopril. His creatinine rose to 2.1 mg/dL, requiring kidney dialysis. Prevention is simple: know the red flags.
Preparing a Sick-Day Kit for Quick Action
Don’t wait until you’re sick to prepare. Build a kit 30 days before flu season (by October 1 in the U.S.). Include:
- Glucose meter with 50+ test strips
- Ketone test strips (minimum 10)
- 7-day supply of diabetes medications
- 6 bottles of sugar-free drinks (12 oz each)
- Electrolyte packets (like Nuun Hydration)
- ADA’s Sick Day Log (printable online)
Store this kit in a visible spot-like your medicine cabinet. A Joslin Diabetes Center survey found 78% of patients who used a prepped sick-day kit avoided hospitalization during illness. One user in Dallas kept his kit in his car during winter trips. When he got sick on a road trip, he had everything he needed to manage his diabetes safely.
Common Mistakes and How to Avoid Them
Even with guidelines, mistakes happen. Here’s what to watch for:
- Stopping all medications: Sulfonylureas (like glipizide) can cause dangerous low blood sugar during illness. Only stop meds that the guidelines specify.
- Ignoring ACE inhibitors: Many patients forget to pause these blood pressure drugs during dehydration. A 2024 study found 41% of patients had conflicting advice between their primary care doctor and endocrinologist about these medications.
- Not testing ketones: DKA can happen even with normal blood sugar levels (euglycemic DKA), especially with SGLT2 inhibitors. Always test if you’re sick.
On Reddit’s r/diabetes forum, a user named “SugarFreeLife” shared: “My endo said keep taking metformin, but the ADA website says stop. Who do I believe when I’m vomiting?” This confusion happens often. The solution? Keep a printed copy of the ADA’s 2023 guidelines in your kit. They’re clear, updated, and free online.
Should I stop metformin if I have a fever?
Yes, stop metformin immediately at the first sign of fever, vomiting, or diarrhea. Metformin increases lactic acidosis risk by 8.3 times when dehydrated. Restart only after your doctor confirms it’s safe. A 2019 NEJM study of 18,450 patients showed continuing metformin during illness caused kidney failure in 1 out of every 30 patients.
Can I keep taking SGLT2 inhibitors if I have a cold?
No. The FDA requires SGLT2 inhibitors to include bold warnings about stopping during illness. These drugs increase DKA risk by 7.2 times when you can’t stay hydrated. Even a mild cold can lead to dehydration. Discontinue immediately and contact your provider.
How often should I check my blood sugar when sick?
Test every 2-4 hours (minimum 6 times per day). The ADA’s 2023 guidelines specify this frequency because blood sugar fluctuates wildly during illness. Skipping tests risks missing dangerous highs or lows. One patient in Texas avoided ER visits by checking her sugar every 2 hours during flu season.
What’s the easiest way to stay hydrated during illness?
Use sugar-free electrolyte drinks like Nuun Hydration or Pedialyte. Aim for 1,500 mL (about 6 cups) daily. Avoid sugary drinks-they spike blood sugar. A 2023 study found patients who used electrolyte packets stayed hydrated 37% better than those who drank plain water alone.
When should I call my doctor during illness?
Call immediately if: ketones are >0.6 mmol/L, blood sugar stays above 240 mg/dL for 6 hours, you can’t keep fluids down, or you feel confused. The ADA’s 24/7 helpline (1-800-DIABETES) answers 92% of calls within 3 minutes. Don’t wait-early intervention prevents hospitalization.
Rene Krikhaar
February 4, 2026 AT 17:04Been diabetic for 15 years these rules are lifesavers. Always check ketones every 2 hours when sick. Keep your kit ready. Don't wait until it's too late.